Pressure armed fuse



June 27, 1950 c. c. LAURITSEN 2,513,185

PRESSURE ARMED FUSE Filed Feb. 5, 1945 v 2 Shets-Sheet 1 fNVENTOR CHARLES C. LAUR/TSEN 4 ATTQRNEY June 27, 1950 Filed Feb. I5, 1945 C. C. LAURITSEN 2 S heetsSheet 2 FIG. 4.

FIG. 6. 6/ :10 I8 67 v 68 J J -62 ,64 g -69 g (Q 63 g 66 70 j 46 68 a .65 I 73 I I HQVENTOR CHARLES C. LAUR/TSHV ATTORNEY gether. is prevented by set-*screw'l2. 'In-the extreme Patented June 27, 1950 warren stares rather orrice as... .diiiiigfjiififjfifia,

of Americans represented by the Secretariat the Navy I :Application l 'ebruary 3, 1945;.SerialNo. '26g120 I 2:01am. J1-

This invention relates to projectile fauzes and particularly torocket projectile nose. fuzes which depend upon airpressure for arming.

A-n objector the present invention is topmvide a nose fuze ior projectiles which will :ar-m inf-light; under the-action of dynamic-air-pressure on its forward portion.

- section in Fig. 1;

Big. 3 is a-sectional view,taken,along linei3 -l-3 -of Fig.1;

1 Fig. I 4 represents .-amodification of the of the invention in-which asafety device inthe .iorm-of a set-backring assembly is employed;

Fig. 5 is a plan-view of-the-fuze shown in sectionin Fig. 4,:and

rFI lg. 6 is an enlar ed view of thesafetysdevice depicted in Fig. 4, showing the .set-backr-ing in the retracted position, :releasing the firing pin. I U

zReierring'nowspecifically to Figs. 1, 2 and 3,

the iuze includes a body member ID and a nose 35 member I! adaptedto be-threadably joined to- Relative motion between these members forward end of nose member 'H and "axially disposed therewith is cylindrical I chamber I3. Somewhat to the rear of cylindrical chamber l3,

:and coaxial therewith, is another ;.cylindrical chamber M of larger diamete gthe two ;-cham -bers-being separated by web I6. Perfo'rations llin web 16 provide air communicationibe'tween the chambers l3 and M. -A bellows diaphragm :p'ressu'res within .thei .blldws: to. compensate for external pressure changes. Firing pin I9 has an extension 20 inside bellows I8, and a shoulder 2| which limits the rearward motion of bellows 18 at the forward face of partition plate 22.

12 .A-ttached to'the-forward 'end of bellows it is v striker pin 23,;prolongation 24 of which extends into the interior of the bellows. Shoulder 26 prevents the longitudinal distension of the bel- 5 lows beyondthe rearwardface of web 16. At itsextreme forward-end striker pin 23 is screwed into nut 21, the-latter having perforations 28. Strikercup 29, havingan-opening '30 in its forward. end fits snugly-.overnut 21, relative motionbetween striker cup 29' and nut 21 being prevented by annular constriction Min striker cup 29. Cap 32 is held tightly against striker cup ZQ-by clamp 3'3,.thereby.efiective1y retaining-springwH-in a compressed condition under striker cup 29. .Cla-mp,- 33 forms its ownhinge v35at one end'and-a pair -of flanges.36 at the oppositeendwhich are adapted to be locked betweenthe head of locking pin '31 and locking cylinder 38; relativeimotion between the latter members is-prevented by the insertion of. safety wire 39' and arming wired!) through holes provided for thatpurpose.

Annular groove 41 at the extreme forward end of the fuze-is filled with a sealing compound to .prevent ent'ry. of moisture around cap 32.

Shutter ring 43 :provides .a cylindrical shutter gchamber (ldwhich receives shutterAB. The latter is pivoted about shutter-pin ll and is urged by shutter spring w-to a position, hereinafter called the ar-med position, in which the shutter =ibears -.ag-ainst-stoppin 49, and spring-loaded detent --.50-;lodges-in .arecess (not shown) provided in I partition plate 22-. y In this armed position, detonator 5l. is alignedwith firing pin !9 and leadei-n 52 whichwprovides explosive communication;with-booster .-53. Figs. 1 and-Edering pin in itsextreme-rearwardposi- U ch-- it,-prevents sh utter 45 from swing- ;iing nto, yarmedwposition. .1 its opjerational-g-use,-thefuze ofwmy inven- Eti'OIl is fixedtozwits projectile. preferably a rocket projectile; anduthe' entire assembly is then 4: =mountedon a'launching mechanism-in any; mannn'er well -knowntto thosei skilled the :art. Safe- ;.-ty =w1ire-39- isremoved. and :only arming wire 34?), which-:is-secured to a rigidpart of the launching :1mechanism,u=isalloW-ed- 1to.,remain :inithe fuze when;theyprojectilezis; readied forrafiring. .Upon niiring; the safety wwiree iil is withdrawn: and" the aientirez-cap.assembly; including capzjfii and clamp r33, isrdorc'edzawayzfrom:thes-nosermember H by action of spring 34 and is carried away in the slipstream of the projectile. Spring 34, in expanding, moves striker pin 23 forward until shoulder 26 contacts web 16. This action also moves bellows l8 forward to its limit. Air, entering chamber 14 through perforations l1 and 28, is compressed by the motion of the projectile and fuze through the air, and the resulting pressure compresses bellows I8 causing its rearward end to move forward, displacing firing pin IS in a forwardv direction thereby. Before firing pin extension 20 contacts striker pin extension 24, firing pin I9 is completely withdrawn from shutter chamber 44, permitting shutter 46 to swing ing pin l9. When the projectile strikes a target, the resulting rearward motion of the striker .pin 23 is transmitted by contact'to the firing pin [9 which strikes the detonator i causing it to explode and detonate the lead-in 52 and booster 53 in turn.

Referring now particularly to Figs. 4, 5 and .6, the fuze there depictedis similar in construction and operation to, that described above but has a modified safety mechanism. Firing pin 60 is provided with a small bleeder passage 6| defined in part by the annular space between a longitudinal bore in the firing pin 60'commu'nieating with the interior of bellows l8 and a filler rod 62 fitting loosely in said bore. A small radial opening 63 in the firing pin completes the bleeder passage; thus, gradual changes in air pressure, such as those due to changes in altitude are equalized within the bellows, but the rapid and extreme pressure change occasioned by movement of the fuzethrough the air is sufficient to collapse the bellows. Firing pin 60 is adapted to slide in sleeve 64 which isprovided with radial openings 65 and fitted with looking balls 66 adapted to fit into. constrictions, such as 61in firing pin 60. Set-back ring 68 initially is held in the forward position by spring 69. An annular recess is provided on the inner surface of set-back ring 68 at its forward endto receive locking balls 66 When set-back ring 68 is in its rearmost position. A safety wire 7| extends through the body of the fuze to prevent-rearward movement of the set-back ring 68, and

consequent release of the firing pin 60. Springloaded safety pin 72 extends radially through the fuze wall and into annular groove 13011 the external surface of set-back ring 68. Retainer band 14 retains safety pin 12 in position to prevent longitudinal movement of the set-back ring 68. Other corresponding parts of the two modifications of the fuze herein described are substantially identical and, therefore; have been assigned the same reference numerals.

Operation of the fuze shown in Fig. 4 is as follows: Initially the fuze is in the condition illustrated. The set-back ring 68 is locked in the forward position by safety Wire H and safety. pin 12. When the fuze with its projectile is placed on the launching mechanism, safety wire H is removed. Upon firing the projectile, the retainer band 14 is stripped free by any suitable means (not shown) releasing the set-back ring 68. The forces of acceleration cause the set-back ring to move rearward and, when annular recess 10 reaches the point opposite the locking balls 66, the latter move into such recess, releasing firing pin 60. At the same time, the air pressure which has been built up aroundbellows l8, as

previously described, collapses the. bellows and 4 withdraws firing pin 60 from its position beside shutter 46, permitting the latter to swing into the armed position. Impact of the fuze with a target initiates the same firing sequence described above in the discussion of the fuze illustrated in Figs. 1, 2 and 3.

While the above is a description of what at 7 present are considered preferred embodiments of -10 about pivot 41 under pressure of shutter spring 48, bringing detonator 5| in alignment. with fir-.

the present invention, it will be understood by those skilled in the art that various changes and modifications may be made therein Without departing from the invention, and it is therefore intended in the appended claims to cover all such changes and modifications as fall within the true scope and spirit of the invention.

I claim:

1. A fuze for projectiles comprising a shutter movable from an unarmed to an armed position, a firing pin initially holding said shutter in its unarmed position, a bellows connected with said firing pin, means defining a chamber surrounding said bellows, and openings adapted to subject said chamber to air pressure incidental to movement of the fuze through the air, thereby to collapse said bellows and withdraw said firing pin from said shutter, thereby to permit movement of the shutter to its armed position, and a striker pin protruding into the bellows in confronting relationship with the-continuous end of said firing pin.

2. A fuze construction for rocket-propelled projectiles comprising a body structure defining a bellows cavity, a bellows in said cavity, a firing pin connected with said bellows and initially occupying an inoperative position, said firing pin being movable to an operative position by said bellows, a striker pin connected with said bellows, positioned for engagement with said firing pin and adapted to protrude from said body structure thereby to be driven against said firing pin upon impact of said fuze against an object, said bellows, and means responsive to forces incidental to acceleration of said fuze and its projectile to release said firing pin for movement in response to said bellows. 1

' CHARLES c. LAURITSEN.

REFERENCES CITED Thefollowing references are of record in the file of this patent:

UNITED STATES PATENTS.

Great Britain ,July 2, 1940 

